Pendulum level with transparent indicators



March 6, 1951 F. J. ALLGEO PENDULUM LEVEL WITH TRANSPARENT INDICATORS Filed Sept. 15, 1947 INVENTOR Fred Jiflllgeo ATTORNEYS Patented Mar. 6, 1951 PENDULUM LEVEL WITH TRANSPARENT INDICATORS Fred J ..Allg eo, San Francisco, Calif., assignor of Johnson, San Francisco,

one-half to Stefan c r Application September 15, 1947, Serial No. 774,085

2' Claims.

The present invention has for one object. the provision of a novel, gravity actuated levelop- ,erative to simultaneously indicatedeviations in planes at right angles to each other, either horizontally or perpendicularly. Another object of the; invention whichdisarranged to read through a full 360 ,scale in each plane of inclination.

A' further object ofj the invention is to provide a ,iievel as above, which is adaptable to many uses, such as commercial, aeronautical, maritime, or militaryythe, designand construction of the device being such that it is readilymounted in position for use, easy to read, andiextremely accurate.

An additional object offthis invention is the provision of a gravity actuated level whichis sturdy and weather-proof. l

A further object of the invention is to pro'vide a simple and inexpensive level, and yet one which will be exceedingly effective for the purpose for which it is designed. These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

n In the drawings: 7 I v Fig. 1 is a sectional elevation of the device.

Fig. 2 is a cross sectional elevation on line 2-2 of Fig. l.

Fig. 3 is a perspective view, reduced, of the housing. Referring now more particularly to the characters of reference on the drawings, the improved levelcomprises a rectangular housing,

indicated generally at I, which housing comprises a pair of substantially square end-heads 2 disposed in spaced-apart facing relation. The

' end-heads 2 are connected together, to form the housing, by a top plate 3, a bottom plate 4, and side plates 5; at least the top and side plates being transparent for the purpose of permitting of ready and easy readin of the level mechanism mounted within the housing, which mechanism comprises:

The end heads 2 are fitted, centrally thereof, with bearing cups 6 removably mounted by screws 1; said cups each carrying a bearing 8. Axially alined spindles 9 are journaled in corresponding ones of the bearings 8 and project into the housing a short distance.

The spindles 9 are fixed, at their inner ends,

' to the center of rotary discs In in the housing running in closely adjacent but spaced relation to provide .a gravity actuated level, ,of the type described,

to dials ll fixed'on the inner face of the endheads 2 concentric to said spindles 9. The dials H, on their outer face, are formed with a 360 scale or calibration l2, while the rotary discs are of transparent material and are scribed with cross-hairs I 3.which read on the 360 scale 12. The transparent, rotary discs H) are connected together, for. rotation in unitary relation, by

means ofa'pair ofbars l4 fixed, and extending between, said discs Ill parallel to, but on, opposite "sides of, an axialline extending between the -spindles..9..

A pair. of discs l: are disposed fbetween the bars. .14 in spaced facing'relation to each other, and said bars M are each affixed diametrically to the corresponding one ofglthe transparent discs 15., by means of screiw's fljfi.

The transparent'discs [5 are of a diameter which closely approaches the diameter of the rotary discs'lfl, but as mounted are at right angles to thelatter and symmetrical to the axis of the same.

A pair. of concentric but spaced-apart rings I! are fixed between the discs I 5 adjacent the periphery thereof, whereby to form an annular channel l8 between said rings; the rings l1 and channel l8v having an axis co-extensive with the axis of the discs l5.

A quantity of mercury I 9 is disposed in the annular .channel I8; such mercury providing the pendulum efiect for the rotary discs Ill which read onthe scales I 2 of the fixed dials ll.

. 'Within the confines of the innermost rin ll,

the device-is fitted with a rotary pendulum formed on opposite sideswith matching 360 .scales 2|, and cross-hairs 22 on the transparent discs l5 read on corresponding ones of the scales 2|. The rotary pendulum 20 is fitted, centrally thereof, with bearing seats 23, and spindles 24 threadingly engage through the bars M in alined relation and provide needle bearings 25 working in the seats 23 in supporting relation to the rotary pendulum 20. The spindles 24 are adjustably maintained in correct setting by lock nuts 26; said spindles 24 extendin axially outwardly beyond said lock nuts 26, and there carrying balancing balls 21 in threaded-on and consequently adjustable relation.

As the spindles 24 are alined and extend axially of the assembly of the transparent discs l5 and concentric rings l1, said balancing balls 21 may be manipulated to adjust the proper position of the pendulum made up of the members l4, l5, l1 and IS.

The rotary pendulum 20, which is preferably partly cut away in the upper half, as shown, is formed be ow its axis, or in the lower half, with a cavity 28 having a threaded rod 29 extending thereacross parallel to the axis of the spindles 9. An adjustment or balancing ball 30 is threaded on rod 29 adjustment of said .ball providing the means for initial accurate setting :of the crosshairs 22 of each disc IS in neutral or zero position with respect to the corresponding 360 scale 2|. Access to the ball 30 for adjusting it is had through either one or the other ofnthe discs .15 by means of ports 3| in said discs.

At the bottom and adjacent the corners the support whose inclination-is to be ascertained, .4

either vertically or perpendicularly, thedescribed-v level will provide simultaneous and easy read ings ofthe inclination in rightngle planes. The 'idegreeof inclination in one'planeis ascertained by reading the cross hairs of-eitherrotary disc 410 on the corresponding fixed dial 11, while the degree of inclinationrin a plane at a right angle to said one .plane is ascertained by reading --the .cross hairs 22 of onedisc l5 on the corresponding ,;sca1e' 2l of the rotary pendulum 20.

Q ,Itis ,thus possibleto obtain accurate simultaneous readings in right angle p1anes;'this being very advantageous .for many purposes to which "the device maybe put. Y I

. The described device is relativelysimple and 'jinexpensive in its structure; and yet provides a ,practical, convenient, and easy-to-read instrumentality.

The transparent top plate ,3, and side plates 5 are each provided with anumber of cross hairs ,33. The central cross hairA on the top plate 3 registers to right or left of the transverse axis of the interior unit, while the horizontal cross hairs B of the side plates '5 register above and be- .low the longitudinal axis of the unit, and can be ,readon peripheral degree markings 34 on the end discs l0. By reading any given set or sets of the cross hairs 3,3 simultaneously on adjacent ,cross hairs 22 and the corresponding scale 2|, therefore, the device has high accuracy and in addition the exact angular positionsof the housling, relative to a true level, are determinable as is especially desirable .for aircraft or gunnery adaptations.

From the foregoing description it will be readily While this specification sets forth in detail the present and preferred construction of the device,

still in practice such deviations from such detail mayjbe resorted to as do not form a departure fronpthe spirit of the invention, as defined by the appended claims.

Having thus described the invention, the followingis claimed -as:new and useful, and-upon which Letters Patent are desired:

'1. A level comprising a pair of spaced apart supports, a calibrated dial on the inner face of .eacli'fsupport, a :pair of spaced apart bars pivoted .;at their ends in the supports co-axially of the dials,'.a transparent disc on each end of the bars, cach tdisc overlying the dial on one of the supports, a radial hairline scribed on each transparent'disc in front of the adjacent dial, a pair of sp'acedapart transparent discs fixed to the bars with the axes of such last named discs disposed transversely of the longitudinal axis of the bars, acylindrical pendulum pivoted between the discs c'o a'x'i'a'lly therewith, -a calibrated scale "on each face of the pendulum, and a' hair line scribed on each of said "last named discs in front of thescale on the adjacent face of the pendulum. f;

2. A level as in claim 1 in which the pendulum is provided with 'a transversely disposed cutout cavity below its central axis, a-threaded pin disposed across the cavity, a ball threaded for adiustment along the threaded pin, each disc being provided with an openport adjacent'the ball.

FRED J. ALLGEQ,

I 'aEFEn NoEs CITED I V I} 5 The following references are of record in the file of this patent: I

UNITED STATES PATENTS "Number Date Name 268,826 Robertson Dec. 12,1882 603,368 Vredenburgh et'al. May 3, 1898 1,258,597 'Mladinich Mar. '15, 1918 1,288,579 'Hawley ,Dec. 24, 1918 1,308,795 McCormack July 8, 1919 1,310,444 Rohm July'22, 1919 1,359,474 Wernick Nov. 16, 1920 1,426,645 Hornbeck Aug. 22, 1922 1,433,513 Luce Oct. 24, 1922 1,440,275 Cerveny Dec. 26, 1922 2,189,516 Fujimoto Feb. 6, 1940 2,384,586 Allgeo .Sept. 11, 1945 FOREIGN PATENTS Number Country Date 13,828 Great Britain 1914 77,672 Germany 1894 152,819 Great Britain 1920 

